cbzip2inputstream.java

Use the links below to download a source distribution of Ant from one of our mirrors. It is good pra

            } finally {
                this.data = null;
                this.in = null;
            }
        }
    }

    private int bsR(final int n) throws IOException {
        int bsLiveShadow = this.bsLive;
        int bsBuffShadow = this.bsBuff;

        if (bsLiveShadow < n) {
            final InputStream inShadow = this.in;
            do {
                int thech = inShadow.read();

                if (thech < 0) {
                    throw new IOException("unexpected end of stream");
                }

                bsBuffShadow = (bsBuffShadow << 8) | thech;
                bsLiveShadow += 8;
            } while (bsLiveShadow < n);

            this.bsBuff = bsBuffShadow;
        }

        this.bsLive = bsLiveShadow - n;
        return (bsBuffShadow >> (bsLiveShadow - n)) & ((1 << n) - 1);
    }

    private boolean bsGetBit() throws IOException {
        int bsLiveShadow = this.bsLive;
        int bsBuffShadow = this.bsBuff;

        if (bsLiveShadow < 1) {
            int thech = this.in.read();

            if (thech < 0) {
                throw new IOException("unexpected end of stream");
            }

            bsBuffShadow = (bsBuffShadow << 8) | thech;
            bsLiveShadow += 8;
            this.bsBuff = bsBuffShadow;
        }

        this.bsLive = bsLiveShadow - 1;
        return ((bsBuffShadow >> (bsLiveShadow - 1)) & 1) != 0;
    }

    private char bsGetUByte() throws IOException {
        return (char) bsR(8);
    }

    private int bsGetInt() throws IOException {
        return (((((bsR(8) << 8) | bsR(8)) << 8) | bsR(8)) << 8) | bsR(8);
    }

    /**
     * Called by createHuffmanDecodingTables() exclusively.
     */
    private static void hbCreateDecodeTables(final int[] limit,
                                             final int[] base,
                                             final int[] perm,
                                             final char[] length,
                                             final int minLen,
                                             final int maxLen,
                                             final int alphaSize) {
        for (int i = minLen, pp = 0; i <= maxLen; i++) {
            for (int j = 0; j < alphaSize; j++) {
                if (length[j] == i) {
                    perm[pp++] = j;
                }
            }
        }

        for (int i = MAX_CODE_LEN; --i > 0;) {
            base[i] = 0;
            limit[i] = 0;
        }

        for (int i = 0; i < alphaSize; i++) {
            base[length[i] + 1]++;
        }

        for (int i = 1, b = base[0]; i < MAX_CODE_LEN; i++) {
            b += base[i];
            base[i] = b;
        }

        for (int i = minLen, vec = 0, b = base[i]; i <= maxLen; i++) {
            final int nb = base[i + 1];
            vec += nb - b;
            b = nb;
            limit[i] = vec - 1;
            vec <<= 1;
        }

        for (int i = minLen + 1; i <= maxLen; i++) {
            base[i] = ((limit[i - 1] + 1) << 1) - base[i];
        }
    }

    private void recvDecodingTables() throws IOException {
        final Data dataShadow     = this.data;
        final boolean[] inUse     = dataShadow.inUse;
        final byte[] pos          = dataShadow.recvDecodingTables_pos;
        final byte[] selector     = dataShadow.selector;
        final byte[] selectorMtf  = dataShadow.selectorMtf;

        int inUse16 = 0;

        /* Receive the mapping table */
        for (int i = 0; i < 16; i++) {
            if (bsGetBit()) {
                inUse16 |= 1 << i;
            }
        }

        for (int i = 256; --i >= 0;) {
            inUse[i] = false;
        }

        for (int i = 0; i < 16; i++) {
            if ((inUse16 & (1 << i)) != 0) {
                final int i16 = i << 4;
                for (int j = 0; j < 16; j++) {
                    if (bsGetBit()) {
                        inUse[i16 + j] = true;
                    }
                }
            }
        }

        makeMaps();
        final int alphaSize = this.nInUse + 2;

        /* Now the selectors */
        final int nGroups = bsR(3);
        final int nSelectors = bsR(15);

        for (int i = 0; i < nSelectors; i++) {
            int j = 0;
            while (bsGetBit()) {
                j++;
            }
            selectorMtf[i] = (byte) j;
        }

        /* Undo the MTF values for the selectors. */
        for (int v = nGroups; --v >= 0;) {
            pos[v] = (byte) v;
        }

        for (int i = 0; i < nSelectors; i++) {
            int v = selectorMtf[i] & 0xff;
            final byte tmp = pos[v];
            while (v > 0) {
                // nearly all times v is zero, 4 in most other cases
                pos[v] = pos[v - 1];
                v--;
            }
            pos[0] = tmp;
            selector[i] = tmp;
        }

        final char[][] len  = dataShadow.temp_charArray2d;

        /* Now the coding tables */
        for (int t = 0; t < nGroups; t++) {
            int curr = bsR(5);
            final char[] len_t = len[t];
            for (int i = 0; i < alphaSize; i++) {
                while (bsGetBit()) {
                    curr += bsGetBit() ? -1 : 1;
                }
                len_t[i] = (char) curr;
            }
        }

        // finally create the Huffman tables
        createHuffmanDecodingTables(alphaSize, nGroups);
    }

    /**
     * Called by recvDecodingTables() exclusively.
     */
    private void createHuffmanDecodingTables(final int alphaSize,
                                             final int nGroups) {
        final Data dataShadow = this.data;
        final char[][] len  = dataShadow.temp_charArray2d;
        final int[] minLens = dataShadow.minLens;
        final int[][] limit = dataShadow.limit;
        final int[][] base  = dataShadow.base;
        final int[][] perm  = dataShadow.perm;

        for (int t = 0; t < nGroups; t++) {
            int minLen = 32;
            int maxLen = 0;
            final char[] len_t = len[t];
            for (int i = alphaSize; --i >= 0;) {
                final char lent = len_t[i];
                if (lent > maxLen) {
                    maxLen = lent;
                }
                if (lent < minLen) {
                    minLen = lent;
                }
            }
            hbCreateDecodeTables(limit[t], base[t], perm[t], len[t], minLen,
                                 maxLen, alphaSize);
            minLens[t] = minLen;
        }
    }

    private void getAndMoveToFrontDecode() throws IOException {
        this.origPtr = bsR(24);
        recvDecodingTables();

        final InputStream inShadow = this.in;
        final Data dataShadow   = this.data;
        final byte[] ll8        = dataShadow.ll8;
        final int[] unzftab     = dataShadow.unzftab;
        final byte[] selector   = dataShadow.selector;
        final byte[] seqToUnseq = dataShadow.seqToUnseq;
        final char[] yy         = dataShadow.getAndMoveToFrontDecode_yy;
        final int[] minLens     = dataShadow.minLens;
        final int[][] limit     = dataShadow.limit;
        final int[][] base      = dataShadow.base;
        final int[][] perm      = dataShadow.perm;
        final int limitLast     = this.blockSize100k * 100000;

        /*
          Setting up the unzftab entries here is not strictly
          necessary, but it does save having to do it later
          in a separate pass, and so saves a block's worth of
          cache misses.
        */
        for (int i = 256; --i >= 0;) {
            yy[i] = (char) i;
            unzftab[i] = 0;
        }

        int groupNo     = 0;
        int groupPos    = G_SIZE - 1;
        final int eob   = this.nInUse + 1;
        int nextSym     = getAndMoveToFrontDecode0(0);
        int bsBuffShadow      = this.bsBuff;
        int bsLiveShadow      = this.bsLive;
        int lastShadow        = -1;
        int zt          = selector[groupNo] & 0xff;
        int[] base_zt   = base[zt];
        int[] limit_zt  = limit[zt];
        int[] perm_zt   = perm[zt];
        int minLens_zt  = minLens[zt];

        while (nextSym != eob) {
            if ((nextSym == RUNA) || (nextSym == RUNB)) {
                int s = -1;

                for (int n = 1; true; n <<= 1) {
                    if (nextSym == RUNA) {
                        s += n;
                    } else if (nextSym == RUNB) {
                        s += n << 1;
                    } else {
                        break;
                    }

                    if (groupPos == 0) {
                        groupPos    = G_SIZE - 1;
                        zt          = selector[++groupNo] & 0xff;
                        base_zt     = base[zt];
                        limit_zt    = limit[zt];
                        perm_zt     = perm[zt];
                        minLens_zt  = minLens[zt];
                    } else {
                        groupPos--;
                    }

                    int zn = minLens_zt;

                    // Inlined:
                    // int zvec = bsR(zn);
                    while (bsLiveShadow < zn) {
                        final int thech = inShadow.read();
                        if (thech >= 0) {
                            bsBuffShadow = (bsBuffShadow << 8) | thech;
                            bsLiveShadow += 8;
                            continue;
                        } else {
                            throw new IOException("unexpected end of stream");
                        }
                    }
                    int zvec = (bsBuffShadow >> (bsLiveShadow - zn)) & ((1 << zn) - 1);
                    bsLiveShadow -= zn;

                    while (zvec > limit_zt[zn]) {
                        zn++;
                        while (bsLiveShadow < 1) {
                            final int thech = inShadow.read();
                            if (thech >= 0) {
                                bsBuffShadow = (bsBuffShadow << 8) | thech;
                                bsLiveShadow += 8;
                                continue;
                            } else {
                                throw new IOException("unexpected end of stream");
                            }
                        }
                        bsLiveShadow--;
                        zvec = (zvec << 1) | ((bsBuffShadow >> bsLiveShadow) & 1);
                    }
                    nextSym = perm_zt[zvec - base_zt[zn]];
                }

                final byte ch = seqToUnseq[yy[0]];
                unzftab[ch & 0xff] += s + 1;

                while (s-- >= 0) {
                    ll8[++lastShadow] = ch;
                }

                if (lastShadow >= limitLast) {
                    throw new IOException("block overrun");
                }